The new McNuggets are smaller and have less fat and fewer calories than the current version, with the restaurant looking to meet a growing preference for chicken breast meat, the Chicago Tribune reported Sunday.

The redesigned chicken chunks will be phased in over the next six weeks to the fast food giant’s 13,600 U.S restaurants.

Since McDonald’s first rolled out McNuggets in 1983, they have been one of the company’s most popular entrees — especially among children.

But the company says extensive consumer tests over the past six months show the time is right to shift from a McNugget that is 30 percent dark meat to one that’s 100 percent white meat.

“It’s clear now that consumers prefer white meat, so we started to work on how we might evolve the McNugget to a situation where it is now all white meat,” said Wendy Cook, vice president of menu innovation at the Oak Brook, Ill.-based chain.

The new six-piece McNuggets will contain 260 calories, down from 310 calories, and 16 grams of fat, four fat grams less than the older product.